Theoretical analysis of dimension chains when restoring the landing socket for liner sleeve collar in the depth of the engines D-245 and D-260

Introduction. Up to 23% of all cylinder blocks of used engines D-245 and D-260 have worn out sockets for the liner sleeve collar in-depth and shall be discarded. The aim of the study was to increase the durability of the cylinder blocks of the mentioned above engines by processing the sockets in the repair size with the subsequent installation of adjusting washers. Materials and Methods. In the article, the method of dimensional analysis was used to solve the problems. Based on the data presented in the technical documentation, the dimension chains were calculated when the piston moves to the lower and upper dead center. Results. The conducted studies of dimension chains found that when the piston moves to the lower and upper dead center with gaps in the joints corresponding to the new units, the distance between the bottom of the piston and the head of the unit can be from 0.488 to 1.592 mm, and with gaps corresponding to the permissible during operation - from -0.035 to 1.15 mm. According to the results of calculations, the depth of the socket under the liner collar in the boring process should be within 9.4+JJ4 mm, i.e. in the range of 9.44...9.48 mm. Discussion and Conclusion. As a result of the study, the dimensional analysis found that the permissible value for milling the block stopping plane is 0.35 mm, and the depth of the liner collar when installing the adjusting washer with a thickness of 0.4 mm shall be from 9.45 to 9.47 mm.